gdb/gdbserver/win32-i386-low.c

   1 /* Copyright (C) 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   2
   3    This file is part of GDB.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include "server.h"
  19 #include "win32-low.h"
  20 #include "i386-low.h"
  21
  22 #ifndef CONTEXT_EXTENDED_REGISTERS
  23 #define CONTEXT_EXTENDED_REGISTERS 0
  24 #endif
  25
  26 #define FCS_REGNUM 27
  27 #define FOP_REGNUM 31
  28
  29 #define FLAG_TRACE_BIT 0x100
  30
  31 #ifdef __x86_64__
  32 /* Defined in auto-generated file reg-amd64.c.  */
  33 void init_registers_amd64 (void);
  34 #else
  35 /* Defined in auto-generated file reg-i386.c.  */
  36 void init_registers_i386 (void);
  37 #endif
  38
  39 static struct i386_debug_reg_state debug_reg_state;
  40 static unsigned dr_status_mirror;
  41 static unsigned dr_control_mirror;
  42
  43 static int debug_registers_changed = 0;
  44 static int debug_registers_used = 0;
  45
  46 /* Update the inferior's debug register REGNUM from STATE.  */
  47
  48 void
  49 i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
  50 {
  51   if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
  52     fatal ("Invalid debug register %d", regnum);
  53
  54   /* debug_reg_state.dr_mirror is already set.
  55      Just notify i386_set_thread_context, i386_thread_added
  56      that the registers need to be updated.  */
  57   debug_registers_changed = 1;
  58   debug_registers_used = 1;
  59 }
  60
  61 CORE_ADDR
  62 i386_dr_low_get_addr (int regnum)
  63 {
  64   gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
  65
  66   return debug_reg_state.dr_mirror[regnum];
  67 }
  68
  69 /* Update the inferior's DR7 debug control register from STATE.  */
  70
  71 void
  72 i386_dr_low_set_control (const struct i386_debug_reg_state *state)
  73 {
  74   /* debug_reg_state.dr_control_mirror is already set.
  75      Just notify i386_set_thread_context, i386_thread_added
  76      that the registers need to be updated.  */
  77   debug_registers_changed = 1;
  78   debug_registers_used = 1;
  79 }
  80
  81 unsigned
  82 i386_dr_low_get_control (void)
  83 {
  84   return dr_control_mirror;
  85 }
  86
  87 /* Get the value of the DR6 debug status register from the inferior
  88    and record it in STATE.  */
  89
  90 unsigned
  91 i386_dr_low_get_status (void)
  92 {
  93   /* We don't need to do anything here, the last call to thread_rec for
  94      current_event.dwThreadId id has already set it.  */
  95   return dr_status_mirror;
  96 }
  97
  98 /* Watchpoint support.  */
  99
 100 static int
 101 i386_insert_point (char type, CORE_ADDR addr, int len)
 102 {
 103   switch (type)
 104     {
 105     case '2':
 106     case '3':
 107     case '4':
 108       return i386_low_insert_watchpoint (&debug_reg_state,
 109                                          type, addr, len);
 110     default:
 111       /* Unsupported.  */
 112       return 1;
 113     }
 114 }
 115
 116 static int
 117 i386_remove_point (char type, CORE_ADDR addr, int len)
 118 {
 119   switch (type)
 120     {
 121     case '2':
 122     case '3':
 123     case '4':
 124       return i386_low_remove_watchpoint (&debug_reg_state,
 125                                          type, addr, len);
 126     default:
 127       /* Unsupported.  */
 128       return 1;
 129     }
 130 }
 131
 132 static int
 133 i386_stopped_by_watchpoint (void)
 134 {
 135   return i386_low_stopped_by_watchpoint (&debug_reg_state);
 136 }
 137
 138 static CORE_ADDR
 139 i386_stopped_data_address (void)
 140 {
 141   CORE_ADDR addr;
 142   if (i386_low_stopped_data_address (&debug_reg_state, &addr))
 143     return addr;
 144   return 0;
 145 }
 146
 147 static void
 148 i386_initial_stuff (void)
 149 {
 150   i386_low_init_dregs (&debug_reg_state);
 151   debug_registers_changed = 0;
 152   debug_registers_used = 0;
 153   dr_status_mirror = 0;
 154   dr_control_mirror = 0;
 155 }
 156
 157 static void
 158 i386_get_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 159 {
 160   /* Requesting the CONTEXT_EXTENDED_REGISTERS register set fails if
 161      the system doesn't support extended registers.  */
 162   static DWORD extended_registers = CONTEXT_EXTENDED_REGISTERS;
 163
 164  again:
 165   th->context.ContextFlags = (CONTEXT_FULL
 166                               | CONTEXT_FLOATING_POINT
 167                               | CONTEXT_DEBUG_REGISTERS
 168                               | extended_registers);
 169
 170   if (!GetThreadContext (th->h, &th->context))
 171     {
 172       DWORD e = GetLastError ();
 173
 174       if (extended_registers && e == ERROR_INVALID_PARAMETER)
 175         {
 176           extended_registers = 0;
 177           goto again;
 178         }
 179
 180       error ("GetThreadContext failure %ld\n", (long) e);
 181     }
 182
 183   debug_registers_changed = 0;
 184
 185   if (th->tid == current_event->dwThreadId)
 186     {
 187       /* Copy dr values from the current thread.  */
 188       struct i386_debug_reg_state *dr = &debug_reg_state;
 189       dr->dr_mirror[0] = th->context.Dr0;
 190       dr->dr_mirror[1] = th->context.Dr1;
 191       dr->dr_mirror[2] = th->context.Dr2;
 192       dr->dr_mirror[3] = th->context.Dr3;
 193       dr_status_mirror = th->context.Dr6;
 194       dr_control_mirror = th->context.Dr7;
 195     }
 196 }
 197
 198 static void
 199 i386_set_thread_context (win32_thread_info *th, DEBUG_EVENT* current_event)
 200 {
 201   if (debug_registers_changed)
 202     {
 203       struct i386_debug_reg_state *dr = &debug_reg_state;
 204       th->context.Dr0 = dr->dr_mirror[0];
 205       th->context.Dr1 = dr->dr_mirror[1];
 206       th->context.Dr2 = dr->dr_mirror[2];
 207       th->context.Dr3 = dr->dr_mirror[3];
 208       /* th->context.Dr6 = dr_status_mirror;
 209          FIXME: should we set dr6 also ?? */
 210       th->context.Dr7 = dr_control_mirror;
 211     }
 212
 213   SetThreadContext (th->h, &th->context);
 214 }
 215
 216 static void
 217 i386_thread_added (win32_thread_info *th)
 218 {
 219   /* Set the debug registers for the new thread if they are used.  */
 220   if (debug_registers_used)
 221     {
 222       struct i386_debug_reg_state *dr = &debug_reg_state;
 223       th->context.ContextFlags = CONTEXT_DEBUG_REGISTERS;
 224       GetThreadContext (th->h, &th->context);
 225
 226       th->context.Dr0 = dr->dr_mirror[0];
 227       th->context.Dr1 = dr->dr_mirror[1];
 228       th->context.Dr2 = dr->dr_mirror[2];
 229       th->context.Dr3 = dr->dr_mirror[3];
 230       /* th->context.Dr6 = dr_status_mirror;
 231          FIXME: should we set dr6 also ?? */
 232       th->context.Dr7 = dr_control_mirror;
 233
 234       SetThreadContext (th->h, &th->context);
 235       th->context.ContextFlags = 0;
 236     }
 237 }
 238
 239 static void
 240 i386_single_step (win32_thread_info *th)
 241 {
 242   th->context.EFlags |= FLAG_TRACE_BIT;
 243 }
 244
 245 #ifndef __x86_64__
 246
 247 /* An array of offset mappings into a Win32 Context structure.
 248    This is a one-to-one mapping which is indexed by gdb's register
 249    numbers.  It retrieves an offset into the context structure where
 250    the 4 byte register is located.
 251    An offset value of -1 indicates that Win32 does not provide this
 252    register in it's CONTEXT structure.  In this case regptr will return
 253    a pointer into a dummy register.  */
 254 #define context_offset(x) ((int)&(((CONTEXT *)NULL)->x))
 255 static const int mappings[] = {
 256   context_offset (Eax),
 257   context_offset (Ecx),
 258   context_offset (Edx),
 259   context_offset (Ebx),
 260   context_offset (Esp),
 261   context_offset (Ebp),
 262   context_offset (Esi),
 263   context_offset (Edi),
 264   context_offset (Eip),
 265   context_offset (EFlags),
 266   context_offset (SegCs),
 267   context_offset (SegSs),
 268   context_offset (SegDs),
 269   context_offset (SegEs),
 270   context_offset (SegFs),
 271   context_offset (SegGs),
 272   context_offset (FloatSave.RegisterArea[0 * 10]),
 273   context_offset (FloatSave.RegisterArea[1 * 10]),
 274   context_offset (FloatSave.RegisterArea[2 * 10]),
 275   context_offset (FloatSave.RegisterArea[3 * 10]),
 276   context_offset (FloatSave.RegisterArea[4 * 10]),
 277   context_offset (FloatSave.RegisterArea[5 * 10]),
 278   context_offset (FloatSave.RegisterArea[6 * 10]),
 279   context_offset (FloatSave.RegisterArea[7 * 10]),
 280   context_offset (FloatSave.ControlWord),
 281   context_offset (FloatSave.StatusWord),
 282   context_offset (FloatSave.TagWord),
 283   context_offset (FloatSave.ErrorSelector),
 284   context_offset (FloatSave.ErrorOffset),
 285   context_offset (FloatSave.DataSelector),
 286   context_offset (FloatSave.DataOffset),
 287   context_offset (FloatSave.ErrorSelector),
 288   /* XMM0-7 */
 289   context_offset (ExtendedRegisters[10 * 16]),
 290   context_offset (ExtendedRegisters[11 * 16]),
 291   context_offset (ExtendedRegisters[12 * 16]),
 292   context_offset (ExtendedRegisters[13 * 16]),
 293   context_offset (ExtendedRegisters[14 * 16]),
 294   context_offset (ExtendedRegisters[15 * 16]),
 295   context_offset (ExtendedRegisters[16 * 16]),
 296   context_offset (ExtendedRegisters[17 * 16]),
 297   /* MXCSR */
 298   context_offset (ExtendedRegisters[24])
 299 };
 300 #undef context_offset
 301
 302 #else /* __x86_64__ */
 303
 304 #define context_offset(x) (offsetof (CONTEXT, x))
 305 static const int mappings[] =
 306 {
 307   context_offset (Rax),
 308   context_offset (Rbx),
 309   context_offset (Rcx),
 310   context_offset (Rdx),
 311   context_offset (Rsi),
 312   context_offset (Rdi),
 313   context_offset (Rbp),
 314   context_offset (Rsp),
 315   context_offset (R8),
 316   context_offset (R9),
 317   context_offset (R10),
 318   context_offset (R11),
 319   context_offset (R12),
 320   context_offset (R13),
 321   context_offset (R14),
 322   context_offset (R15),
 323   context_offset (Rip),
 324   context_offset (EFlags),
 325   context_offset (SegCs),
 326   context_offset (SegSs),
 327   context_offset (SegDs),
 328   context_offset (SegEs),
 329   context_offset (SegFs),
 330   context_offset (SegGs),
 331   context_offset (FloatSave.FloatRegisters[0]),
 332   context_offset (FloatSave.FloatRegisters[1]),
 333   context_offset (FloatSave.FloatRegisters[2]),
 334   context_offset (FloatSave.FloatRegisters[3]),
 335   context_offset (FloatSave.FloatRegisters[4]),
 336   context_offset (FloatSave.FloatRegisters[5]),
 337   context_offset (FloatSave.FloatRegisters[6]),
 338   context_offset (FloatSave.FloatRegisters[7]),
 339   context_offset (FloatSave.ControlWord),
 340   context_offset (FloatSave.StatusWord),
 341   context_offset (FloatSave.TagWord),
 342   context_offset (FloatSave.ErrorSelector),
 343   context_offset (FloatSave.ErrorOffset),
 344   context_offset (FloatSave.DataSelector),
 345   context_offset (FloatSave.DataOffset),
 346   context_offset (FloatSave.ErrorSelector)
 347   /* XMM0-7 */ ,
 348   context_offset (Xmm0),
 349   context_offset (Xmm1),
 350   context_offset (Xmm2),
 351   context_offset (Xmm3),
 352   context_offset (Xmm4),
 353   context_offset (Xmm5),
 354   context_offset (Xmm6),
 355   context_offset (Xmm7),
 356   context_offset (Xmm8),
 357   context_offset (Xmm9),
 358   context_offset (Xmm10),
 359   context_offset (Xmm11),
 360   context_offset (Xmm12),
 361   context_offset (Xmm13),
 362   context_offset (Xmm14),
 363   context_offset (Xmm15),
 364   /* MXCSR */
 365   context_offset (FloatSave.MxCsr)
 366 };
 367 #undef context_offset
 368
 369 #endif /* __x86_64__ */
 370
 371 /* Fetch register from gdbserver regcache data.  */
 372 static void
 373 i386_fetch_inferior_register (struct regcache *regcache,
 374                               win32_thread_info *th, int r)
 375 {
 376   char *context_offset = (char *) &th->context + mappings[r];
 377
 378   long l;
 379   if (r == FCS_REGNUM)
 380     {
 381       l = *((long *) context_offset) & 0xffff;
 382       supply_register (regcache, r, (char *) &l);
 383     }
 384   else if (r == FOP_REGNUM)
 385     {
 386       l = (*((long *) context_offset) >> 16) & ((1 << 11) - 1);
 387       supply_register (regcache, r, (char *) &l);
 388     }
 389   else
 390     supply_register (regcache, r, context_offset);
 391 }
 392
 393 /* Store a new register value into the thread context of TH.  */
 394 static void
 395 i386_store_inferior_register (struct regcache *regcache,
 396                               win32_thread_info *th, int r)
 397 {
 398   char *context_offset = (char *) &th->context + mappings[r];
 399   collect_register (regcache, r, context_offset);
 400 }
 401
 402 static const unsigned char i386_win32_breakpoint = 0xcc;
 403 #define i386_win32_breakpoint_len 1
 404
 405 static void
 406 init_windows_x86 (void)
 407 {
 408 #ifdef __x86_64__
 409   init_registers_amd64 ();
 410 #else
 411   init_registers_i386 ();
 412 #endif
 413 }
 414
 415 struct win32_target_ops the_low_target = {
 416   init_windows_x86,
 417   sizeof (mappings) / sizeof (mappings[0]),
 418   i386_initial_stuff,
 419   i386_get_thread_context,
 420   i386_set_thread_context,
 421   i386_thread_added,
 422   i386_fetch_inferior_register,
 423   i386_store_inferior_register,
 424   i386_single_step,
 425   &i386_win32_breakpoint,
 426   i386_win32_breakpoint_len,
 427   i386_insert_point,
 428   i386_remove_point,
 429   i386_stopped_by_watchpoint,
 430   i386_stopped_data_address
 431 };